Hasan N, Rafii M Y, Abdul Rahim H, Nusaibah S A, Mazlan N, Abdullah S
Faculty of Applied Science, Universiti Teknologi MARA, Kuala Pilah, Negeri Sembilan, Malaysia
Laboratory of Food Crops, Institute of Tropical Agriculture, Universiti Putra Malaysia, Selangor, Malaysia.
Genet Mol Res. 2017 Jan 23;16(1):gmr-16-01-gmr.16019280. doi: 10.4238/gmr16019280.
Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. Therefore, information on genetic resistance and virulence stability are vital to increase our understanding of the molecular basis of blast disease resistance. The present study set out to elucidate the resistance pattern and identify potential simple sequence repeat markers linked with rice blast disease. A backcross population (BCF), derived from crossing MR264 and Pongsu Seribu 2 (PS2), was developed using marker-assisted backcross breeding. Twelve microsatellite markers carrying the blast resistance gene clearly demonstrated a polymorphic pattern between both parental lines. Among these, two markers, RM206 and RM5961, located on chromosome 11 exhibited the expected 1:1 testcross ratio in the BCF population. The 195 BCF plants inoculated against M. oryzae pathotype P7.2 showed a significantly different distribution in the backcrossed generation and followed Mendelian segregation based on a single-gene model. This indicates that blast resistance in PS2 is governed by a single dominant gene, which is linked to RM206 and RM5961 on chromosome 11. The findings presented in this study could be useful for future blast resistance studies in rice breeding programs.
水稻稻瘟病是世界上最具毁灭性的水稻病害之一。真菌病原体稻瘟病菌是水稻稻瘟病的致病因子。培育抗病品种是实现水稻可持续生产的最优选方法。然而,病原体基因组的遗传可塑性阻碍了抗病品种的有效性。因此,关于遗传抗性和毒力稳定性的信息对于增进我们对稻瘟病抗性分子基础的理解至关重要。本研究旨在阐明抗性模式并鉴定与水稻稻瘟病相关的潜在简单序列重复标记。利用标记辅助回交育种培育了一个由MR264和邦苏塞里布2号(PS2)杂交产生的回交群体(BCF)。携带稻瘟病抗性基因的12个微卫星标记在两个亲本系之间明显呈现出多态性模式。其中,位于第11号染色体上的两个标记RM206和RM5961在BCF群体中表现出预期的1:1测交比例。对195株BCF植株接种稻瘟病菌P7.2小种后,在回交后代中显示出显著不同的分布,并基于单基因模型遵循孟德尔分离规律。这表明PS2中的稻瘟病抗性由一个单一显性基因控制,该基因与第11号染色体上的RM206和RM5961连锁。本研究的结果可能对未来水稻育种计划中的稻瘟病抗性研究有用。